The invention is in the field of image display composition, and more particularly is in the field of systems which combine graphics and video images for display on a single display device.
In systems which utilize a display to represent and explain services to interested persons, it is often desirable to display a scene including video and graphics imagery. For example, the display of program material with spoken narrative explanation will be incomprehensible to a deaf person. However, the provision of written narrative in a section of the program display will permit a deaf person to comprehend both the visual and verbal content of the program. Manifestly, the written portion must be presented on the same display as the visual program if the deal viewer is to appreciate the verbal and visual segments simultaneously.
One way of providing the written verbal narrative on the same display is to utilize a conventional graphics generator to generate common alphanumeric characters. Normally, the operation of the generator is directed by a program controller which would insure that the written verbal content output by the generator is synchronized with the visual presentation.
In other applications, it is useful to provide a display system which can display not only written program narration, but a board set of graphics images and symbols which can be displayed in any combination with video images. Such a system would be flexible and adaptable to a wide variety of uses.
Therefore, it is evident that there exists a need for a display apparatus having the capability of enabling the display of both graphics and video images in a variety of combinations.